Seal plug

Abstract

A seal plug for conduits is disclosed having a plug core including at least one radially-expansible seal member for sealing the conduit in which it is disposed, while permitting passage of cables or the like therethrough. Until required for the cable or cables, the passages in the seal plug are closed by removable pin inserts, retainer means being provided to hold the inserts in place. The plug includes longitudinal compression means to bring the seal member into sealing contact with the conduit wall. Each passage may open to the circumference of the respective seal member via slits to permit sideways insertion of the cable therein.

I claim: 
     
       1. A seal plug for use in a conduit having a plurality of passages therethrough for receiving a respective number of elongated members therein to pass them through the seal plug, said seal plug comprising: a plug core including at least one radially-expansible seal member having a respective plurality of passages therethrough and adapted for insertion into said conduit in unexpanded condition, the plug core closing and sealing said conduit when inserted therein and in radially-expanded condition, and also when in radially-expanded condition sealing around an elongated member that is inserted in its respective passage;   a pair of seal plug pressure members each having a respective plurality of passages therethrough and between which the seal member is sandwiched so as to be expanded radially upon axial movement of the pressure members toward each other;   a removable insert for each passage closing the respective passage in said seal member, and sealed in the passage along the length thereof when the plug core is in the radially-expanded condition, each removable insert consisting of a headed pin passing through the seal member and the pressure members;   retainer means engaging said removable headed pins to retain them in their respective passages, the said retainer means consisting of an apertured plate having a respective plurality of apertures therein and having each pin head engaged in a respective aperture thereof of smaller diameter than the pin head, each pin head being forcible through the respective aperture for removal of the pin by the application of a suitable force to the pin shaft, and   axial compression means passing through the seal member, the pressure members and the retainer member for moving the pressure members toward each other to axially compress the seal member and effect the said radial expansion thereof.   
     
     
       2. A seal plug as claimed in claim 1, wherein the plug core includes two end members of electrically insulating material each having a respective plurality of passages therethrough and through which each removable insert passes, each end member being interposed between a respective pressure member and the adjacent face of the said at least one seal member. 
     
     
       3. A seal plug as claimed in claim 1, wherein each passage in the said at least one seal member is connected to the circumference of the seal member by a slit permitting sideways insertion of the respective elongated member into the passage through the slit. 
     
     
       4. A seal plug as claimed in claim 1, wherein the plug core includes at least two seal members disposed end to end, each seal member having a respective plurality of passages therethrough, each seal member being of frusto-conical shape, the smaller diameter end of one member abutting the larger diameter end of the other member, and the smaller ends of the seal members being disposed toward the end of the plug receiving a higher pressure. 
     
     
       5. A seal plug as claimed in claim 1, wherein the said at least one seal member, the end members and the pressure members all have a respective aperture therein which are aligned with one another and through which passes an alignment pin for holding the members in alignment with one another. 
     
     
       6. A seal plug as claimed in claim 1, wherein the axial compression means for radially expanding the said at least one seal member consists of a non-removable axial bolt and nut member. 
     
     
       7. A seal plug as claimed in claim 1, wherein one of said pressure members is of smaller diameter to permit its insertion into a conduit to be sealed by the plug, and the other pressure member is of larger diameter to engage an end of the conduit. 
     
     
       8. A seal plug as claimed in claim 1, wherein the head of each headed pin is of hemispherical shape.